21523000000000 has 200 divisors, whose sum is σ = 53757445667112. Its totient is φ = 8608800000000.

The previous prime is 21522999999911. The next prime is 21523000000039. The reversal of 21523000000000 is 32512.

It is a tau number, because it is divible by the number of its divisors (200).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 999989239 + ... + 1000010761.

Almost surely, 2^{21523000000000} is an apocalyptic number.

21523000000000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21523000000000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26878722833556).

21523000000000 is an abundant number, since it is smaller than the sum of its proper divisors (32234445667112).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21523000000000 is an frugal number, since it uses more digits than its factorization.

21523000000000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 21586 (or 21530 counting only the distinct ones).

The product of its (nonzero) digits is 60, while the sum is 13.

Adding to 21523000000000 its reverse (32512), we get a palindrome (21523000032512).

The spelling of 21523000000000 in words is "twenty-one trillion, five hundred twenty-three billion", and thus it is an aban number.